Holding element of plastic

ABSTRACT

A holding element fastener formed of molded plastic for fastening within a support opening and having a base body and two resilient fingers for extending through the support opening. The fingers stand at an acute angle to each other, and when in the mounted condition grip behind the support opening. The base body and the resilient fingers define an approximately V-shape triangular inter-space and each of the resilient fingers is provided on its outer circumference with two inwardly extending open areas which reduce the total amount of plastic required and simplify the operation of molding the holding element fastener. The open areas are located on opposite sides of a laterally extending middle stay in the form of a relatively thin rib. The upper limit of each middle stay is defined by a separate transverse outwardly extending cross stay which joints to the upper end of the respective resilient finger and the associated middle stay.

BACKGROUND OF THE INVENTION

The subject invention relates to a plastic holding element for fasteninginside a support opening. The element includes a base body and twooppositely disposed resilient fingers arranged thereon for extendingthrough the support opening at an acute angle with each other. In theinstalled condition, the fingers grip behind the support opening. Ineach case, the base body and the resilient fingers define anapproximately triangular interspace.

Such holding elements are already broadly known in the prior art whereinto a base body are connected two resilient fingers which lie oppositeeach other. Typically, another element is present at a location above asealing lip (see U.S. Pat. Nos. 3,909,883 and 3,678,797). It is adisadvantage in these known constructions that their design results in athick accumulation of the plastic material in the zone of the resilientfingers. As a consequence, exact accuracy of size of these resilientfingers is not possible. Moreover, the thick accumulation of the plasticmaterial results in an undesired shrinking of material during coolingafter the molding process. As a consequence, during production a slowinjection of plastic is necessary. Also, in the final product, aconstant checking of quality is necessary.

Also in the prior art are other holding elements with rectangles atright angles to each other instead of the resilient fingers (see U.S.Pat. No. 3,412,437, and French Patent 2,426,179). Also known is thearrangement of a slot between the resilient fingers (see U.S. Pat. No.3,213,500). These known constructions also do not meet the requirementof accuracy of measurement because of their special shaping.

The present invention addresses the problem of designing a holdingelement of the kind mentioned so that, in a simple manner, a large orthick accumulation of material does not result and in production aconstant good quality of finished product is assured.

BRIEF STATEMENT OF THE INVENTION

This problem is solved, according to the invention, by the fact that theresilient fingers are provided on their outer circumference with openareas or spaces. Through these open areas, the advantages are given ofmore rapid injection times, a prevention of deformation by latershrinkage, an exact accuracy of measurement, a prevention of internalcavities, and a saving of material, as well as a better or easiermounting in a support opening.

In a further development of the invention, each resilient finger mayhave a middle stay, to which the open area or space adjoins on bothsides. Here, the middle stay is limited in the upper zone by a crossstay. Moreover, the resilient fingers have, in the zone of thetriangular interspace, a surface parallel to one side of the triangle,while in each case the two surfaces of the resilient fingers stand at anequal angle with the base body. The surfaces are limited in the upperzone by the cross stay, and in the lower zone by a step of graduationdivided by the middle stay. In the front zone, the resilient fingers mayrun in a wedge form defined with four rectangles at right angles to eachother in cross section, formed by the middle stays and the open areas.

In a further development of the invention, the base body is designedrectangular in cross section and may be joined by a circumferentialsealing lip which lies opposite the resilient fingers. On the under sideof the base body parallel to the middle stays is arranged a stayextending up to the base body. This stay may be wider than the twomiddle stays of the resilient fingers.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in detail below, with reference to theexample of execution represented in the drawing, wherein:

FIG. 1 is a side view, partially in section, of a holding element formedin accordance with the preferred embodiment;

FIG. 2 is a front view of the holding element of FIG. 1;

FIG. 3 cross section taken along line III--III of FIG. 1; an

FIG. 4 a cross section taken along line IV--IV of FIG. 2.

cl DETAILED DESCRIPTION OF THE DRAWINGS

Referring more particularly to the drawings wherein the showings are forthe purpose of illustrating a preferred embodiment only, and not for thepurpose of limiting same, FIGS. 1 and 2 show the holding element ascomprising essentially a plastic base body 2 having a surroundingsealing lip 14 joined thereto in the upper zone, as well as resilientfingers 3 and 4 joined in the lower zone beneath the lip 14. Theresilient fingers 3 and 4, as well as the base body 2, delimit in theinner zone an approximately triangular intermediate space 5 and 6 sothat the resilient fingers are correspondingly given their elasticityand are free to deflect inward toward the base body 2.

The resilient fingers 3 and 4 are provided on their outer circumferencewith open areas or recesses 7, 7' and 8, 8', respectively. Eachresilient finger 3, 4, has a middle stay 9, on both sides of which theopen areas 7, 7' and 8, 8', adjoin. In the upper zone, the middle stay 9passes, in each case, into a cross stay 10 which can catch behind theedge of a support opening.

The resilient fingers 3, 4 have, in each case, in the zone of thetriangular intermediate space, 5, 6, a surface 11 and 12, respectively,parallel to one side of the triangle. These two surfaces 11 and 12, ofthe resilient fingers 3, 4, stand in each case at the same angle withthe base body 2. As shown in FIGS. 1, 2 and 3, the surfaces 11, 12 arelimited in the upper zone by the cross stay 10, and in the lower zone bya stepped or graduated portion 13, divided by a middle stay 9.

From FIGS. 1, 2 and 4 it can be seen that the resilient fingers 3, 4 onthe front side, rise up in a wedge form configuration defined by fourrectangles (in cross section) located at right angles to each other. Therectangular cross sections are formed by the middle stays 9 and the freeor open spaces 7, 7' and 8, 8'. In the lower zone, these rectangles runout into a nose piece 17.

As shown in FIG. 1, surrounding elastic sealing lip 14 is arranged onthe base body 2 and lies opposite the resilient fingers 3, 4. A stay 15is formed on the under side of lip 14 and on the under side extendsparallel to the middle stay 9 to the base body 2. This stay 15 has thefunction of guiding the fastener within a support opening duringinstallation of the fastener. Above the surrounding sealing lip 14, theholding element according to the invention is provided with a closingelement 16, for example, a pipe holding, a closing pin or anotherelement for the holding of an object (not shown in detail).

Through the special shaping of the resilient fingers 3 and 4, with theiropen areas 7, 7' and 8, 8', respectively, an undesired accumulation ofmaterial is prevented, so that, besides a saving of material, there isgiven a more rapid injection time, and a greater accuracy and control oftolerances. This results in improved quality in the finished product.Cavities are prevented, and because the front or lead-in parts of theresilient fingers are designed with a cross shape and associated openareas, are a rapid and easy mounting in a support opening is assured.

What is claimed is:
 1. A holding element fastener formed of molded plastic for fastening within a support opening and having a base body and two resilient fingers arranged thereon lying opposite each other for extending through the support opening, said fingers standing at an acute angle to each other, and when in the mounted condition gripping behind said support opening, the base body and the resilient fingers, defining an approximately V-shape open triangular inter-space, each of the resilient fingers (3, 4) are provided on their outer circumference with two inwardly extending open areas which reduce the total amount of plastic required and simplify the molding operation of said holding element fastener, said open area (7, 7'; 8, 8") located on opposite sides of laterally extending middle stay in the form of a relatively thin rib, the middle stay of each resilient finger extending outwardly from the middle of the respective finger and being aligned with the middle stay of the other resilient finger, the upper limit of each middle stay being defined by a separate transverse outwardly extending cross stay which joins to the upper end of the respective resilient finger and the associated middle stay.
 2. The holding elements according to claim 1 wherein the resilient fingers (3, 4), define open triangular inter-spaces (5, 6), and wherein each finger has a surface (11, 12) parallel to one side of the triangular inter-space with the two surfaces (11, 12) of the resilient fingers (3, 4) lying at the same angle with the base body (2).
 3. The holding element according to claim 1 wherein the resilient fingers (3, 4) run up on their front side, in wedge form with four rectangles in cross section positioned at right angles to each other and formed by the middle stay (9) and the open areas (7, 7', 18, 8'). 